93 4.0 d 30 front. Believe np 231 tc (I have 2 high 4 high and 4 low part time) the fork for 4 low is broken but 4 high, I can feel and hear the front drive shaft engage and spin but I have no power to either front wheel. I adjusted the linkage but I don't think I needed to it was only off a little. I'm not sure what else to check.

 

any noises and what fork are you referring to the one inside the dana 30 if thats the one you need to replace it because it wont engage the front axles leaving you with open diff

 

drive shafts locked when in 4x4 no power to wheels front axle issues

 

The four low fork in the tc is broken. What in my front axle would I be looking for?

 

I guess a little better description might help you guys help me more. In 4 low I get gear reduction to the rears but it doesn't engage front ds at all. In 4 high I can hear and feel the front ds spinning, the best way I can describe it is a little bit of vibes and almost like smooth metals rubbing (not grinding or banging). Both 4x4 modes don't supply any power to the front wheels. I haven't had opportunity to open up the diff to see what's going on because I'm unemployed right now and can't afford to poke around in crap too much.

 

Is it a vacuum disconnect axle or a non disco? Seeming how you have the 231 i would guess its the vacuum disco axle. Problem sounds like it is probably a vacuum issue. Check your lines from the vacuum bucket( big black egg looking thing under the hood) to your TC. Also check the lines from the vacuum bucket down to the shift housing on the passenger side of the axle.

If the vaccuum lines are all good then you may have a broken shift fork inside the shift housing on the axle. The housing is a simple 4 bolts to take off and just pull it off, you will lose a little bit of gear oil so be prepared for that but its really not enough to worry about if you cant replace the fluid right away. Check the collar that slides on the actual shafts, and check that the shift fork isnt broken.

I dont know 100% but im pretty sure that if 4lo wont work due to the tc, then the 4high wont either.

 

Its not vacuum I don't think. Only hose on the front diff is the breather. The front ds doesn't even try to engage in 4 low but it does in 4 high, I just have no power. If I open up the pumpkin what would I be looking for? My knowledge of differentials internals is minimal but I can usually figure crap out after poking around. Also how difficult of a job is it to rebuild a tc? Another off topic question, how would I tell if I have an lsd in the rear? Rear is c 8.25.

 

the vac lines dont go to the front diff. they go to the shift housing on the passenger side of the axle. If it doesnt have this housing then its not vacuum actuated.

I doubt it is anything in your differential causing this problem, but if it is you would be looking for big chunks of metal in the bottom of the diff housing and look at your ring gear and pinion gear and see if they are destroyed. Or your spider gears destroyed.


The housing and actuator look like this.

 

Okay well its 100% not vacuum then. The TC is shifting into 4 high and engaging the front ds. So I'm thinking diff issues? Other opinions would be great.

 

in other words you have 4x4in 4 high but not in 4 low correct

 

Since its non vacuum then I'm assuming its an issue with some gear inside the diff right? Cause the diff is constantly spinning the ds correct?

 

It engages the shaft but delivers no power to the wheels

 

so you do not have 4wheel drive no matter where you put the transfercase lever correct

 

You can tell by the year the OP doesn't have a front disco guys. Try this KRAZYNEZZ. Put the T case in 2 hi and see if you can spin the front drive shaft then try it in every other mode. It should never be able to turn when the front end is on the ground so it would be a front end issue if it spins in 2 hi, A T case AND front end problem if it spins in any other mode

 

Correct. I will try spinning by hand but I'm pretty sure I candidate cause I was grabbing onto it a bunch while adjusting the linkage and it didn't turn much.